Archive for September 23, 2010


Equinoxes and Daylight Saving

#daylightSavings As long as I’m on the subject of the #equinoxes, I’d like to point out that day length (and the times of sunset and sunrise, and even the sun’s path across the sky) is symmetrical around the summer solstice. If the purpose of daylight savings is really to encourage people to take advantage of the fact that sunrise is earlier in the summer, its starting and ending times should also be symmetrical around the solstice. They aren’t. Apparently politicians don’t realize how day length works. They have decreed that daylight time starts shortly before the spring equinox (day and night equal), but ends more than 6 weeks after the fall equinox. Here in Fairbanks, we’re getting up before sunrise in November regardless, and shifting off daylight savings only moves the 5 pm traffic from dusk to full dark. Daylight savings should start about the same length of time before the spring equinox as it ends after the fall equinox, as that would have sunrise and sunset times about the same at the start and end of daylight time.

Alaska a few days before the southward equinox

FEASTDAY: #scifi #time #calendar The intercalary day 182 days after Yearday, approximating the date of the southward equinox. As aphelion is near the southward equinox on Central, Feastday is generally within a day or two of the equinox, and is a holiday  on Central. Here on Earth, the southward Equinox is today, September 22 2010, at 7:09 pm Alaska Daylight Time. (That’s 8:09 PDT, 9:09 MDT, 10:09 CDT, 11:09 EDT, and September 23 for most of Eurasia and Africa.